The present invention relates to a tissue scraper element for medical use, and more particularly to such an element usable in extracting undesired body tissue, e.g. a cataracted natural eye lens, by mechanical vibratory contact to disintegrate the tissue and by accompanying flushing fluid flow removal of the disintegrated tissue from the tissue site, the element including a shank, mountable on a hand held instrument for longitudinal back and forth vibratory movement, and having a crosswise extending tip terminating in a laterally outwardly directed scraper edge, a flow channel in the tip communicating a flow passage in the shank with a mouth adjacent the scraper edge to accommodate such flushing fluid flow.
U.S. Pat. No. 3,589,363 to Banko and Kelman discloses a hand held instrument and method for breaking apart and removing by flushing fluid flow undesired material such as tissue from a body site. The instrument contains vibratory movement means connected to a longitudinal shank having an axial bore leading to a mouth at its projecting straight tip, and a conduit leading to an opening at the shank exterior, such that axial vibratory movement of the tip, when pressed axially against the tissue, breaks up the tissue by jack-hammer-like action, for removal by flow of fluid from a source to the site via one of the mouth and opening and its return with broken up tissue via the other of the mouth and opening to a suction source.
This patent teaching has been for break up and removal of cataracted eye lens tissue per known surgical procedures. Such procedures are effected through a corneal incision kept as small as possible to minimize patient trauma. In this regard, it is desirable to remove all tissue debris from the posterior capsule.
However, it has been found that in using the straight tip instrument of this patent for such purposes, the procedures is burdened by awkwardness in the positioning of the instrument in the surgeon's hand under the extant vibratory conditions, especially when attempting to break up portions of the cataracted lens tissue in remote portions of the posterior capsule in relation to the fixed position of the necessarily small corneal incision. This awkwardness leads to uncomfortable hand and finger positions of the surgeon when holding the vibrating instrument and manipulating it in relation to that fixed location of the corneal incision for bringing the free end of its straight tip into proper "head-on" position for breaking up the lens tissue in the inherently confined spatial areas involved.
While the instrument of this patent may be provided with a radially extending, sharp pointed projection, this is only used to tear the anterior wall of the capsule covering the lens by back and forth tearing action to obtain access to the lens prior to initiation of the tissue breaking apart procedure. This projection would be of no value in breaking apart the main mass of the lens tissue within its capsule, especially considering that the projection has a pointed end and is positioned with that end remote from the tip mouth through which the flushing fluid flows.
On the other hand, the back and forth jack-hammer-like action of the straight tip of the instrument of this patent, which is used for the actual breaking up of the lens tissue, operates by way of axial or longitudinal direction percussion impulse exerted perpendicularly against the tissue surface as anvil, inherently resulting in a coarse shattering of the tissue.
As a result, the surgeon must take pains to manipulate the tip through many diverse angular positions, while the shank extends through the relatively small incision, to be able to apply the leading transverse face of the longitudinal straight tip in "head-on" relation with the lens tissue, as the very nature of the percussion impulse action is such that the axially vibrating tip makes head-on face-to-face contact with the tissue surface. Also, care must be taken to avoid unduly pressing the tip against the tissue surface of the posterior wall of the capsule for fear of puncturing or otherwise damaging unnecessarily that wall which is intended to remain intact.
It would be desirable to provide an instrument of the type shown in this patent, but which is easier and faster to use and which avoids the aforesaid disadvantages by permitting more efficient breaking apart and flushing removal of the undesired tissue from the treatment site, thus reducing the time required for the surgical procedure of cataracted lens removal while at the same time simplifying the motions which the surgeon must carry out.